Furnace door structure with spring and cam retention means



Feb. 5, 1952 E, c, WEBB 2,584,404

FURNACE DOOR STRUCTURE WITH SPRING AND CAM RETENTION MEA S Filed July 14, 1947 2 SHEETS-SHEET 1 T D .12 f7 f.

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A 7T GENE Y Feb. 5, 1952 E. c. WEBB 2,584,404

FURNACE DOOR STRUCTURE WITH SPRING AND CAM RETENTION MEANS Filed July 14, 1947 Sl-IEETS-SHEET 2 T Q 1% a INVENTOR. i; Q 'r/weszdfiiabb Patented Feb. 5, IQSZ FURNACE noon STRUCTURE WITH SPRING. AND A RETENTION'MEANS Ernest (J. Webb,"Bay Village, Ohio, assignor to Iron Fireman Manufacturing Company, Portland, Oreg.

Application July 14, 1947, Serial No. 760,809

This invention relates generally to furnaces and particularly to a closure for furnaces.

The main objectof this invention is toprovide a furnace door which will be simple to'construct and install and which will afford a' perfect seal at the junction of the door and thedocr opening.

The second object i'sto provide a door with a self-closing-spring mechanism. I

The third object is to protect the exterior of the door from the radiant heat of the furnace. The fourth object-is to construct a door and hinge therefor so that the-swinging radius will be greatly reduced thereby adapting itself foruse in close quarters and inplaces where the old type of swinging door would be objectionable. I accomplish these and other objects in the manner set forth in the following specification as illustrated in the accompanying drawings, in

which:

Fig. l is a fragmentary perspective view ofv a furnace front showing the door in an open position.

Fig. 2 is a horizontal section taken alongthe line '2 2 in Fig. 1.

Fig. 3' is a fragmentary sectiontaken through the spring hinge and showing the doorin a closed position.

Fig. 4 is a front elevation of the device showing a portion cut away to disclose the working parts.

Fig. 5 is a section taken along the line 55 in Fig. 4.

Fig. 6 is an enlarged fragmentary plan of the spring hinge showing the unloaded.

Similar numbers of reference refer to the same or similar parts throughout the several views.

Referring in detail to the drawing, there is shown a furnace front I!) having a fire door opening ll around which is placed a door frame E2. The head I3 of the door frame I2 constitutes a strap for the spring hinge M which is in the form of a channel which receives the stationary cam l5 which is welded to the frame l2. Mounted in the cam I5 is a vertical hinge pin 16 whose lower and journalizes the bearing H which is secured to the door sill l8 by means of the bolt 19. Mounted on the lower end of the pin I6 is a hinge arm 20 which is secured to the pin l6 by the set screw 2|.

Connecting the outer ends of the members I4 and 20 is a vertical spindle 22 on which is secured a collar 23 by means of the set screw 24. Above the collar 23 and pierced by the spindle 22 is an angle clip 25 to which is secured the 3 Claims. (01. 110-113) 30 and hold it to a comfortable temperature.

- 2 I baffle plate 26 whose nates' in a flange 28 which is flush. with the face 29 of the fire door 30 which in turn is connected rigidly to the baffle plate 26 by the lugs 3|,

which are attached to the plate 26 by the bolts 32 and to the door 30 by the screws 33.

Mounted on the inner side of the baffle plate 26 isa refractory insulation 34 which is held in place by the facing 35 of heat resisting metal, having the flanged edges 36 and which is secured to the baffle plate 26 by the through bol It will be noted that the cam 15 has an undercut. shoulder or drop offv 38. which normally en-.

gages the end 39 of a leaf spring 40 which is secured to the interior of the strap [4 by the bolts 4|. outwardly, the end- 39 rides on the cam surface 42 affording a drag or holding action to the door tending to hold it in any position to which it is moved.

In some instances, however, a freer action is face 44 is concentric with the pin l6 and has a.

radius substantially the same as the curved surface 45 of the fixed cam 46,although in practice it is desirable to have the surface 45 extend slightly beyond the surface 44, a spring 41 urges the unloader 43 toward the cam 46.

It follows that as the spring tip 39 rides off of the surface 45 it rides upon the unloader 43, thereby eliminating the major portion of the drag on the door.

It will be noted that the face 29 0f the door 30 is separated from the furnace front H] allowing air to pass along the interior of the fire door It is desirable to provide a seal 48 of asbestos or similar material around the door openin and it is against this seal which the flange 28 seats when the. door is closed; that is, the door floats to a perfect sealing seat and the door is either urged toward this seat orcan be moved to any desired position.

While I have thus illustrated and described my invention, it is not my desire to be limited to the precise form shown herein, and I intend to cover such forms and modifications of the invention as fall fairly within the appended claims.

I claim:

1. A door frame, a door, and means operatively hinging said door to said frame, said means comprising a hinge link means, a first means inturned portion 21 termi- It will be noted that, as the door 30 swings dperatively connecting one end of said link means in hinged relation to said door frame, a second means operatively connecting th other end of said link means in hinged relation to said door, the hinging axis of said first means being in spaced parallel relation to the hinging axis of said second means, a cam on said door frame, and a resilient cam follower means fixed to said link means in operative relation to said cam, said cam being formed with a cylindrical surface of uniform radius about the hinging, axis of said first means, said cylindrical surface terminating angularly at a recess formed in said cam, and the free end of said cam follower being adapted to move ofi said cylindrical surface into said recess as said door nears its closed position against said frame, whereby as said door is moved away from said door frame and said cam follower rides pin and approaches said opening the part of said spring means riding said cam surface, will move from the cylindrical surface of said cam toward the receding surface of said cam and thereby urge said door member towards its limit position adjacent said opening and whereby, as said door member is rotated about said pin away from its limit position adjacent said opening and as said spring means moves from adjacent said receding surface of said cam to said cylindrical surface of said cam, the force of said spring means urging said door member towards said limit position will vanish.

3. The mechanism of claim 2 in which said cam is characterized by having said cam surface formed with a surface of greater radius than said cylindrical surface interposed in said surface bethe surface of said cam from said recess to said cylindrical surface, door closing energy will be stored in said cam follower and as said door nears said door frame and said cam follower rides the surface of said cam from said cylindrical surface to said recess, door closing energy will be given up by said resilient cam follower.

2. A wall having an opening therein, a door for closing said opening, and hinge means supporting said door on said wall, said hinge means comprising, a stationary hinge member secured to said wall, a hinge pin supported on said hinge member, a door member carried on said hinge pin in hinged relation to said hinge member, a stationary cam member supported on said wall, a spring means secured to said door member, said spring means being adapted to rest on the cam surface of said cam in resiliently strained relation thereto, said spring means being adapted to ride over the cam surface ofsaid cam as said door member is rotated toward or away from said wall about said pin axis, said cam surface being of cylindrical form for part of its length, the axis of said cylindrical cam surface coinciding with the axis of said hinge pin, said cam surface being parallel to the axis of said pin, said cam surface extending in width axially of said pin,

and said cam surface being formed at one end to recede abruptly towards the axis of said pin, whereby as said door member rotates about said tween said cylindrical surface and said receding surface and in which said mechanism includes an unloader member carried on said wall and oscillatable aboutvthe axis of said pin, said unloader member being formed in part with ;a cylindrical surface the center of which surface is the'axis of said pin and the radius of which surface is greater than the radius of the cylindrical surface of said cam and lesser than the radius of said surface of greater radius, said unloader member being interposed-in the path of said spring member as said spring member passes from said surface of greater radius of said cam into the angular space subtended by the cylindrical area of the surface of said cam, whereby as said spring member leaves said surface ofgreater radius it will engage said unloader member and ride'thereon throughout its motion within said angular space. v

ERNEST C. 'WEBB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Whittan1 July 8, 1930 

